Slide fastener



Feb. 23, 1943.

L. w.- scHA'AFF Filed May 2'71 1941 Louis Feta. 3, was

NiTE

SLCIDEFASTENER Louis w. Schaafi, Jackson Heights, N. Y., as-

signor to Waldes Koh-I-Noor, Inc., Long Island City, N. Y., a corporation of New York Application May 21, 1941, Serial No. 395,419

9 Claims. (01.24-205) This invention relates to improvements in slide fasteners and in its more specific aspects.

to improved sliders therefor.

As usually constructed, sliders for the socalled Slide. fasteners comprise front and rear plates connected and spaced by an integral wedge or divider which is so disposed between the plates as to form therewith a Y-shaped race for the interlocking elements carried along the opposed edges of a pair of stringers. As the 'slider is moved along the rows of interlocking elements to disengage the same, the disengaged elements are spread ianwise due to the divergence of the branches of the race, with the result that the stringers and the interlocking elements are causedto gap in unsightly manner. Moreover, as the slider is moved to the limit of its interlocking movement, thus to close the garment or othe'rarticle to which the fastener is applied, the Y-shaped race causes the material of the stringers, and hence of the garment, to bulge and spread in the regionv just above the top of the s1ider,-thus giving thefastening an untidy and unfinished appearance.

It is equally conventional practice to equip sliders of the character under consideration with locking means which are usually operated by the pull tab. Such locking means are es cially provided to effect looking as distinguished from being inherent in the slider construction and deand finished appearance, particularly above the slider when the latter is movedto its fully closed position. By its self-locking properties, the slider maintains itself locked against movement from its closed position or from any partially open position under the influence of, longitudinal stresses or oflateral stresses applied either above or directly through the slider. Moreover, the self-locking characteristics of the slider of the present invention are obtained at no sacrifice to the, required free sliding move-' ment between the slider and the interlockin sign and, when equipped therewith, the locking means necessarily adds to the cost of the article, the over-all bulk of the slider is increased, and, moreover, such locking means oftentimes develop mechanical'faults and are likely to dislocate one or more of the interlocking elements engaged thereby to a degree impairing theutility of the slider as a whole.

The present invention contemplates and pro: vides an improved slider which is characterized by a novelly shaped race for the interlocking elements which, by reason of its unique formation, serves the dua function of \maintaining the rows'of interlocking elements parallel upon their disengagement and which moreover elimi'-.-

nates spreading of the stringers and hence of the garment in the region just above the slider when the fastening is fully closed, and'at the same time of rendering the slider inherently selflocliing without the requirement of extraneous fastening means. 'With thevrows of disengaged interlocking elements always disposed in parallel relation above the slider, unsightly gapping' of the fastener when disengaged is precluded and there also results a fastening having a-neat elements, but, on the other hand, the slider race is so shaped as to permit the desired free sliding movement necessary in slider fastener construction.

The invention further contemplates a slider of novel and improved designand constructional features, which may be economically produced by simplified manufacturing methods requiring aminimum of tooling and assembly steps. The improved slider design also results in aslider which possesses strength, making it substantially, crush-proof due to its ability to withstand crushing pressure, while at the same time the improved design results in a slider whichlisj substantially thinner than looking sliders of known construction.

Moreover, a slider in accordance with the present invention may be embellished to a degree heretofore unknown and hence the present slider relatively great structural may, in addition to the symmetricalicontourina thereof resulting from the basic design, be further embellished so as to enhance its artistic and pleasing appearance.

Other objects will be in part obvious and in part hereinafterpointed out in connection with the following analysis of this invention wherein is illustrated an embodiment of the invention in detail. 7

In the drawing- Fig. 1 is a plan view of a pcrtlon'of a slide fastener employing theslider o! the present invention-and'wh ich illustrates the parallel disposition of theinterlocking elements when disengaged;

Fig. 2 is a longitudinal section through the slider illustrated in Fig. l;

Fig. 3 is an under face view of one of the plates making up the slider as aforesaid;

Fig. 4 is a section illustrating the assembly relationship of front and rear plates of the slider;

Fig. 5 is a plan view of. the slider and it's associated pull tab upon final assembly;

Fig. 6 is a side view of the finally assembled slider;

Fig. '7 is a detail of a preferred form of securing rivet;

Fig. 8 is a section through a modified form of slider; and I Fig. 9 is a detail illustrating a modified form of securing rivet.

will be understood that the invention is not limited to the use of interlocking elements of the particular form illustrated, as other forms thereof may be substituted.

As is well known, fastener interlocking elements of the character illustrated are interlocked and disengagedby a slider which embraces the elements and which is operative to progressively force them into interlocking engagement when the slider is moved along the row of elements in one direction, generally upwardly, and to progressively disengage the elements as the slider moved along the rows thereof in the opposite or downward direction.

Such a slider forms the subject-matter of the present invention and is provided by a body portion having a front plate I6 and a rear plate l1, the plates being secured in'spaced parallel relationship by a rivet I8 as generally indicated in Fig. 7. The front and rear plates are separately formed and are of identical construction. Preferably, the plates are formed complete in a multiple-step die which in one step blanks out the plates flat to include side wing portions and in another die-forming step forms in each blank an integral wedge or divider half-section 20 which is centrally disposed within a circular recess 2| countersunk into the relatively outer face of the blank, and simultaneously therewith bends the wings to extend at right angles to the plate proper to form side flanges 22, 23. The wedge half sections are punched to provide a rectangular rivet opening 24, either during the blanking out operation or the subsequent formng operation. 1

Referring to Figs. 3 and 6, the flanges 22, 23 at their upper ends are sloped or inclined downwardly as at 22a, 23a from the inner face of the plates from which they depend and oppositely with reference to the sloping of the upper ends of related side flanges, whereby the sloping upper ends of the related flanges form downwardly pointed, wedge-shaped side openings at the upper outer corners'of the race. The relatively inner edge defining each said opening is V-shaped and extends substantially between the platesas seen in Fig. 6. The latter figure also will indicate that the so formed corner openings at their wide end have width corresponding to the spacing between the plates and converge to a narrow end of a substantially lesser width than the width of the fastener elements tending to move theremetric center substantially coincides withthe geometric center of the plate. By reference to Fig. 4 wherein two separately formed plates are paired for assembly, it will be seen that the end face of the wedge section 20 of each plate is formed flat and provides an abutment surface for the flat face of the wedge section of the companion plate. Moreover the depth of the wedge half-section as formed on each plate is half that required to properly space the 'paired plates upon the latter being disposed in their assembly relation. Hence, the paired wedge half-sections function as a spacer between the slider plates. By further reference to Fig. 4, the side flanges 22, 23 have lesser depth than the wedge half sections 20, whereby upon pairing of the plates side slots 25 are ,provided along the sides of the slider body for the reception of the stringers I2, l3.

The front and rear plates of the slider are secured together by the rivet l8 which,,as shown, is of split-shank construction, the rivet having a wide head 21 and thinner shank portions 28 which together have rectangular section, the ends of the shanks being winged for ready riveting over. The head 21 is provided with an opening 30 to receive the pintle 3| of a pull tab 32. The shoulder intermediate the rivet head and shanks makes for a firm seating of the rivet head against the outer face of the countersunk recess upon final assembly.

With the front and rear plates paired and spaced by the Wedge half sections, as in Fig. 4, the rivet- I8 is threaded into the rivet openings 24 which extend in alignment, and the lower ends of the rivet shanks are upset, thereby to secure the front and rear plates together in fully assembled relation and against relative twisting movement. By reference to Fig. 6, it will be seen that the rivet head 21 seats in the countersunk recess 2| of the front plate 16 and that the upset ends of its shank are encompassed within the countersunk recess 2| of the companion rear plate I1. Thus, due to the countersinking of the front and rear plates as aforesaid, a slider body of minimum thickness is provided.

By reference to Fig. 3, the slider plates are roughly pear-shaped to provide an open-ended slider body which is outwardly bulged and hence wider at its mid portion than at its top and bottom ends. With the wedge 20 having a symmetrical disposition generally on the geometric center of the slider body, it is necessarily spaced from the head and tail openings of the latter and is further spaced from the inner walls of the side flanges 22, 23. Thus, the slider body provides a race or channel for the interlocking elements [0 and II having upper and lower straight-way portions which are axially. aligned. Above its lower end portion the race is divided by the wedge 20 and branches outwardly and thence inwardly along a gentle curve to reunite above the wedge and form the upper race portion.

As will be seen from Figs. 2 and 3, the spacing between the inner walls of the flanges 22, 23 adjacent their'lower ends is such that the flanges act to cam the fastening elements l0. 1 l into interlocking engagement as the slider is moved upwardly, the flanges at their lowermost ends defining a tail opening which in width corresponds to the width of two interlocked elements plus sliding clearance. As the slider is moved downwardly, the Wedge or divider 20 disengages the interlocked elements and causes opposed ele- ,ments to move along the race branches, each branch having a width corresponding to the width of an interlocking element plus sliding clearance. The distance between the upper ends of the side flanges 22, 23 is greater than the dis tance between the lower ends of the flanges and corresponds to the width of two disengaged clements placed end -to-end, plus sliding clearance,

so that the disengaged elements may, with some clearance between opposed elements, slide freely out of the head opening of the slider as the latter converge relatively inwardly towards each other upon their moving past the wedge and are thereby disposed in parallel relation as they move out of the slider body. Due tothis parallel disposition of the disengaged interlocking elements,

gapping or spreading of the elements and of their associated stringers is prevented both during opening movement and also when the slider is moved to fully closed position.

By reason of the shape of the slider race as described, the slider is inhei ently self-locking. This will be appreciated from a consideration of Fig. 2, from which it will be seen that longitudinal stresses applied to the fastener tend to straighten out the interlocking elements as they bend around the wedge 20. Under this condition the relatively inner ends of the interlocking elementsbind against and frictionally grip the side wall of the wedge, and the outer ends of the interlocking elements adjacent thereto bind ments adjacent thereto bind against the side walls of the wedge and the'inner walls of the side flanges, as well as against the sloped upper ends (22a or 23a) of the related side flanges of the paired plates which form funnel or wedgeshaped locking openings at the upper outer corhers of the race (see Fig. 6) into which the end or leg portions of adjacent fastener elementsv tend to wedge and/or against the defining inner corners of which the said element portions tend to lockingly engage.

When the fastening is. subjected to lateral stresses applied directly through the slider, it will be readily seen that the outer ends of the interlocking elements then within the slider body frictionally hug the inner walls of the side flanges 22, 23 thereof throughout their entire length and relative movement between the slider and the so engaged elements is thereby precluded. I

Moreover, the slider'firmly interlocks with the interlocking elements when the fastening is subjected to so-called wiggling stresses as when the fastener is used on foundation garments. It has been observed that with looking fasteners of known construction these wiggling stresses set up by body movements tend to disengage the locking means from the interlocking elements, with the result that continually applied stresses of this character gradually open the fastening. According to the present construction, the so-called wiggling forces. due to body movement have no effect in disturbing the desired interlocked relationship between the slider and the interlocking elements,

In Fig. 8 there is shown a modified form of slider body, according 'to which the front and rear plates are'devoid of wedge half sections, being formed flat on their; inner faces. A combined wedge and spacer 35 according to the modified proposal is formed as a separate piece and is assembled with the front and rear plates of the slider body by insertion of a rivet such as the rivet l8 in apertures formed therefor in the plates and wedge, and the subsequent upsetting of the rivet end.

In Fig. 9 a modified form of rivet is illustrated, According to the latter form, the rivet generally indicated at 38 has a split head 39 provided with a pull tab hole 40, and a solid shank M, the latter having a swallow-tail end for ready upsetting.

The pull tab pintle may be inserted into hole 40 through the open head as indicated in dotted lines, and the head is thereupon closed.

It will be appreciated that a sliderconstructed as in the foregoing well satisfies the objects of the invention. Thus, by reference to Fig. 2, the

interlocking elements are disposed in parallel row arrangement and accordingly no gapping of the fastening occurs, either during opening or upon full closure thereof. by which the aforesaid parallel disposition of disengaged locking elements is obtained, also imparts effective self-locking features to the slider, the same being inherent in the construction thereof rather than depending on extraneous lockingmeans.

It will'also be self-evident to those skilled in the art that sliders inaccordance with the in vention can be economically produced by simplified methods of manufacture and assembly steps and at a minimum of tooling. Moreover, sliders so produced possess relatively great structural strength by reason of the generally central disposition of the wedge-spacer, the elongated shape thereof, and the substantial area of support provided thereby. Due to this arrangement, the slider body is substantially crush-proof to pressures that tend to collapse or impair the utility of sliders of known construction.

Obviously a slider as described is more artistic and pleasing in appearance than known sliders by reason of the pear-shaped and symmetrical contour of the slider body portion. Further, substantially the whole upper face of the front slider plate, excluding the countersunk recess thereof,

, provides substantial space for embellishment and ornamentation so that by suitably ornamenting the front plate of the slider body there results a 1. A self-locking slider for slide fasteners comprising a pair of plates having depending marginal side flanges, a wedge spacing the plates and cooperating with the plates and .theside flanges thereof to provide an open-ended race through the body for the fastener elements, the upper ends of the related side flanges being inclined to the inner faces ofthe plates from which they depend and oppositely with reference toeach other to The slider race formation of the race when the fastener is subjected to lat- V eral stresses.

2, A self-locking slider for slide fasteners comprising a pair of plates having depending marginal side flanges, a wedge spacing the plate; and

cooperating with the plates and the side flanges thereof to provide an open-ended race through the body for the fastener elements, the upper ends of the related side flanges being downwardly inclined from the inner faces of the plates from which, they depend and oppositely with reference to each other to providea V-shaped corner locking edge extending substantially between the plates at each upper outer corner of the race and on which adjacent fastener elements tending to move sidewardly outof the upper end of the race when the fastener is subjected to lateral stresses are adapted to bear.

3. A self-locking slider for slide fasteners comner of the race and on which adjacent fastener elements tending to move sidewardly out of the upper end of the race when thefastener is subjected to lateral stresses are adapted to bear.

5. A self-locking slider for slide fasteners comprising an open-ended slider body formed by front and back plates having depending marginal side flanges, and an elliptically shaped wedge spacing said plates and cooperating therewith and the side flanges to provide an openended race, the wedge being disposed near the geometric center of the slider body and the side flanges flaring outwardly in their intermediate portion about said wedge and thence converging inwardly at their upper portion and terminating in upper ends disposed intermediate theupper edge of the body and the upper end of the wedge,

I whereby the end portions of the race are disposed prising an open-ended slider body formed by a pair of plates having depending marginal side flanges and a wedge spacing the plates, said wedge cooperating with the plates and the side flanges thereof to provide an elongated race for the fastener elements, the race having relatively upper and lower end portions opening through the open ends of the slider body and intermediate branch portions which curve outwardly from one end portion and thence inwardly to the other end portion, the upper end portion being longitudinally aligned with the lower end portion of the race thereby to dispose opposed fastener elements upon their disengagement in parallel relation, the upper ends of the related side flanges being inclined to the inner faces of the plates from which they depend and oppositely with reference to each other to provide wedge-shaped side openings at the upper outer corners of the race, ,said' openings at their wide end having width corresponding to thespacing between said plates and at their narrow end having width less than the depth of the fastener elements whereby the openings are adapted to wedgingly receive adjacent fastener elements tending to move sidewardly'out of the upper end of the race when the fastener is subjected to lateral stresses.

4. A self-locking slider for slide fasteners comprising an open-ended slider body formed by a pair of plates havingdepending marginal side flanges and a wedge spacing the plates, said wedge cooperating with the plates and the side flanges thereof to provide an elongated race for the fastener elements, the race having relatively upper and lower end portions opening through the open ends of the slider body and intermediate branch portions which curve outwardly from one end portion and thence inwardly to the other end portion, the upper end portion being longitudinally aligned with the lower end portion of the race thereby to dispose opposed fastener elements upon their disengagement in parallel relation, the upper ends of the related side flanges being downwardly inclined from the inner faces of the plates from which they depend and oppositely with reference to each other to provide a V-shaped corner locking edge extending substantially between the plates at each upper outer corin longitudinal alignment, the upper ends of the related side flanges bing downwardly inclined fromthe inner facesof the plates from which they depend and oppositely with reference to each other to provide a V-shaped corner locking edge extending substantially between the plates at each upper outer corner of the race on which adjacent fastener elements tending to move sidewardly out of 'the upper end of the race under the influence of lateral stresses applied to the fastener are adapted to bear.

6. A self-locking slider for slide fasteners comprising an open-ended body formed by a pair of plates of identical construction, each having integrally formed marginal side flanges and a wedge half-section ofelliptical shape depending relatively inwardly therefrom, said half-sections being each provided with an aperture adapted to align with the aperture of the other half-section,

asecuring rivet extending through said apertures for securing the wedge half-sections together in abutting relation, the wedge formed by said sections being disposed near the geometric center of the slider body and the side flanges flaring outwardly in their intermediate portion about said wedge and thence converging inwardly at their upper portion and terminating in upper ends disposed intermediate the upper edge' of the body and the upper end of the wedge, whereby the end portions of the race are disposed in longitudinal alignment, the upper ends of the related side flanges being downwardly inclined from the inner faces of the plates from which they depend and oppositely with reference to each other to provide a V-shaped corner locking edge extending substantially between the plates at each upper outer corner of the race on which adjacent fastener elements tending to move sidewardly out of the upper end of the race under the influence of lateral stresses applied to the fastener are adapted to bear.

7. In a slider for slide fasteners, a slider body formed by a pair of plates of identical construction, each having integrally formed marginal side flanges depending therefrom, an elliptically shaped wedge spacing said plates and disposed near the geometric center thereof, said plates and wedge being each provided with an aligned non-circular aperture, and a securing rivet having a shank of non-circular section corresponding to the shape of said apertures extending therethrough for securing said plates and wedge together and against relative twisting movement.

8. In a slider for slide fasteners, a slider body formed by a pair of plates of identical construction each having integrally formed marginal side flanges and a wedge half-section depending side flanges and an ellipticallv shaped wedge half-section depending therefrom, each half-section being disposed near the geometric center of the plate from which it extends andabutting the half-section of the other plate to form a complete wedge spacing the plates, said half-sections being provided with aligned rectangular apertures, and a securing rivet having a shank of rectangular section extending through said apertures for securing said plates together and against relative twisting movement.

' LOUIS W. SCHAAFF. 

